Well, considering that they fly 10 of those engines with every Falcon9 launch, and so far only a single of them has actually failed (and just shut off), it does

Well, considering that they fly 10 of those engines with every Falcon9 launch, and so far only a single of them has actually failed (and just shut off), it does not seem to be an actual problem so far. It might be interesting to see if this changes as the engines are reflown with the recovered first stages. If this might create an actual safety hazard for manned missions, it all makes sense to postpone a final solution till you are getting close to doing the manned flights. No reason to delay cargo missions for something that might affect manned rating.